Source 250W L250NS-00 Power Supply Unit PSU for DELL Optiplex 390 790 990 3010 Inspiron 537s 540s 545s Slim Desktop DT Systems on m.alibaba.com
Dell PC7068 - 250W Power Supply Unit (PSU) for Dell Studio Inspiron Slim line SFF Model: 530S, 531S, 537s, 540s, Dell Vostro Slim line SFF 200, 200s, 220s, 400 - CPU Medics
Which Dell Optiplex MT (any model 990, etc.) can I change the graphics card without upgrading the PSU? Which GPUs would work? - Quora
Amazon.com: 400W Power Supply Upgrade for Dell Slimline Optiplex 390 790 7GC81 6MVJH : Electronics